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Title: Consequences of Convex Nanopore Chemistry on Confined Water Dynamics

Abstract

A basic understanding of confined water is crucial for developing selective ion transport and water purification membranes, yet the roles of nanopore geometry and functionality on confined water dynamics remain unresolved. We discuss the synthesis of perdeuterated ionic alkylsulfonate amphiphiles and their water-induced self-assembly into lyotropic liquid crystal (LLC) mesophases with well-defined, convex, sulfonate-lined nanopores. Quasielastic neutron scattering (QENS) measurements demonstrate that the water self-diffusion coefficients within these sulfonate-lined convex nanopores depend on the hydration level and amphiphile counterion identity (H+, K+, NMe4+). The consistency of the observed counterion-dependent water dynamics trends with those of carboxylate LLCs is rationalized on the basis of similarities in the counterion spatial distributions in the water-filled channels, which we deduce from electron density maps derived from small-angle X-ray scattering (SAXS) analyses. These findings indicate that water diffusion is systematically faster in sulfonate-lined nanopores as compared to carboxylate-lined pores due to weaker water interactions with the softer and more hydrophobic–SO3 functionalities. These molecular-level insights into the relationships between convex pore wall chemical functionalities, hydrated counterions, and confined water diffusion may inform future development of new nanoporous media.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [2];  [3]; ORCiD logo [4]
  1. Univ. of Wisconsin, Madison, WI (United States)
  2. Univ. of Minnesota, Minneapolis, MN (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Univ. of Wisconsin, Madison, WI (United States); Univ. of Minnesota, Minneapolis, MN (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
OSTI Identifier:
1601776
Grant/Contract Number:  
SC0010328; AC02-06CH11357; NSF-1608115; DMR-1420013
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry
Additional Journal Information:
Journal Volume: 124; Journal Issue: 8; Journal ID: ISSN 1520-6106
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Jackson, Grayson L., Kim, Sung A., Jayaraman, Ashish, Diallo, Souleymane O., and Mahanthappa, Mahesh K. Consequences of Convex Nanopore Chemistry on Confined Water Dynamics. United States: N. p., 2020. Web. doi:10.1021/acs.jpcb.9b10176.
Jackson, Grayson L., Kim, Sung A., Jayaraman, Ashish, Diallo, Souleymane O., & Mahanthappa, Mahesh K. Consequences of Convex Nanopore Chemistry on Confined Water Dynamics. United States. https://doi.org/10.1021/acs.jpcb.9b10176
Jackson, Grayson L., Kim, Sung A., Jayaraman, Ashish, Diallo, Souleymane O., and Mahanthappa, Mahesh K. Mon . "Consequences of Convex Nanopore Chemistry on Confined Water Dynamics". United States. https://doi.org/10.1021/acs.jpcb.9b10176. https://www.osti.gov/servlets/purl/1601776.
@article{osti_1601776,
title = {Consequences of Convex Nanopore Chemistry on Confined Water Dynamics},
author = {Jackson, Grayson L. and Kim, Sung A. and Jayaraman, Ashish and Diallo, Souleymane O. and Mahanthappa, Mahesh K.},
abstractNote = {A basic understanding of confined water is crucial for developing selective ion transport and water purification membranes, yet the roles of nanopore geometry and functionality on confined water dynamics remain unresolved. We discuss the synthesis of perdeuterated ionic alkylsulfonate amphiphiles and their water-induced self-assembly into lyotropic liquid crystal (LLC) mesophases with well-defined, convex, sulfonate-lined nanopores. Quasielastic neutron scattering (QENS) measurements demonstrate that the water self-diffusion coefficients within these sulfonate-lined convex nanopores depend on the hydration level and amphiphile counterion identity (H+, K+, NMe4+). The consistency of the observed counterion-dependent water dynamics trends with those of carboxylate LLCs is rationalized on the basis of similarities in the counterion spatial distributions in the water-filled channels, which we deduce from electron density maps derived from small-angle X-ray scattering (SAXS) analyses. These findings indicate that water diffusion is systematically faster in sulfonate-lined nanopores as compared to carboxylate-lined pores due to weaker water interactions with the softer and more hydrophobic–SO3– functionalities. These molecular-level insights into the relationships between convex pore wall chemical functionalities, hydrated counterions, and confined water diffusion may inform future development of new nanoporous media.},
doi = {10.1021/acs.jpcb.9b10176},
journal = {Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry},
number = 8,
volume = 124,
place = {United States},
year = {Mon Feb 17 00:00:00 EST 2020},
month = {Mon Feb 17 00:00:00 EST 2020}
}

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